Drying apparatus for laundry work



y 4, 1953 H. c. A. ZWAARD- 2,645,035

DRYING APPARATUS FOR LAUNDRY woax Filed Feb 28,- 1949 Patented July 14, 1953 2,645,035 DRYING APPARATUS FOR LAUNDRY WORK Henricus signor to Machinefabriek Reineveld N. Netherlands, a comp C. A. Zwaard, Bijswijk, Netherlands, as-

V., Delft,

any of the Netherlands Application February 28, 1949, Serial No. 78,745

In the Netherlan ds March 2, 1948 3 Claims. (01. 34-439) In laundries, wet or moist, laundered garments are usually dried in apparatus comprising a horizontal, perforated or otherwise apertured drum provided with axially extending ribs or like members on its inner wall and rotatably supported in a stationary, impervious cylinder having at the bottom side an inlet for drying air and at the top side an exhaust opening for moistcarrying air. If the drum contains a load of moist garments and if it is rotated, the garments will be taken along with the ribs in the direction of rotation and be lifted substantially to the top, whence they fall down onto the bottom, where upon the cycle is repeated. The drying air supplied to the drum flows across the garments and through their interstices so as to extract moisture therefrom, which is discharged together with the air. In such apparatus, the length of the path through which the air flows within the drum does not appreciably cXceed the length of the diameter of the drum. Owing thereto, the moist-carrying air exhausted from the drum is still pable of extracting a good deal of moisture from the articles to be dried, so that in many cases only part of said air is discharged and the remainder recycled toimprove the thermal eificiency, but obviously this means an undesirable complication.

The invention has for its object to avoid this inconvenience and to increase the drying capacity of the apparatus simply by increasing the length of the path through which the air moves within the perforated drum. With this object in view, my invention consists herein that in a laundry drying apparatus of the type referred to, the air inlet and the air outlet openings are spaced an angular distance less than about 90 apart as seen in a direction opposite the direction of rotation of the drum, the air inlet being preferably constituted as a more or less tangential slot in the cylinder wall.

Owing to this construction, the drying air flows into the drum at a comparatively high speed and is compelled to move in a swirling path so as to cover an average distance of about twice the diameter of the drum before reaching the exhaust opening. It is thus capable of extracting so much moisture from the articles to be dried that recycling can be dispensed with.

On the diagrammatic drawing, the figure is a cross section of a drying apparatus embodying the invention. In this figure, 3 is the impervious, cylindrical housing, 4 is the apertured drum t a y mounted therein and provided with longitudinal ribs 5 on its inner wall, 6 is the nozzle for connecting the housing to a hot air supply pipe, and l is the adjacent nozzle for connecting the housing to the conduit for exhausting the moisture carrying air and spaced from the hot air inlet nozzle 6 an angular distance less than therefrom in a direction opposite the direction of rotation of the drum and shown closely adjacent thereto. Thus, the outlet or exhaust nozzle is spaced from the hot air inlet nozzle 6 in the direction of rotation of the drum 4 and the path of movement of the moisture extracting hot air, a distance .of substantially twice the diameter of the drum so as to extract a much greater amount of moisture from the articles being dried. This distance, taken circumferentially, exceeds as in a conventional drying apparatus, at least 270 up to nearly 360 as shown. The arrows indicate the path followed by the drying air through drum 4.

As shown, the nozzle 1 is located, in circumferential direction, close to nozzle 6 (as seen in a direction opposite the direction of rotation of drum 4), and the air flows more or less tangentially into housing 3 through a narrow, axially extending slot through the housing 3, preferably vertically or longitudinally thereof parallel to its axis, so that it is compelled within drum 4 to follow a path whose length, as an average, is at least twice that of the diameter of the drum, before reaching the exhaust nozzle. So, said air is capable of extracting a considerable amount of moisture from the articles to be dried, which are continuously lifted by the ribs 5 and tu ble over on one another as they disengage tre a oi the drum near, and often beyond, the thereof.

Since the air is blown (or into housing at a considerable speed direction away from the exhaust opening, it cannot to any appreciable extent reach said'opening, without having covered a path of comparative great length within the drum.

It is to be remarked that the drying air has not for its duty to maintain the garments in motion, since said articles are lifted by the ribs 5. As a matter of course, said ribs may be substituted by equivalent elements such as stud pins or the like, and if the drum is driven at a relatively high speed, said elements could altogether be dispensed with.

It will be appreciated that the desired effect, namely increasing the length of the path of the air in the drum, can already be realized to an appreciable extent if the exhaust opening, instead of being located at an angular distance of 180 beyond the inlet opening, as usual, is spaced therefrom, in the direction of rotation, a distance appreciably exceeding 180 or at least 270 and up to nearly 360 so that the air in its path of travel in extracting moisture will act almost entirely around the circumferences of the housing 3 and drum 4 before being discharged.

Finally, it is to be understood that, although it is preferred for the inlet and the exhaust opening to be provided at the bottom side of the housing, they could also be located near the top, or intermediate between top and bottom.

What I claim is:

1. A laundry drier comprising a stationary impervious cylindrical housing disposed on a horizontal axis, and an apertured drum journalled substantially concentrically Within said housing with the walls of said housing and drum being closely juxtapositioned, said drum being adapted normally to be rotated in one direction, the cylindrical wall of said housing having a single air inlet opening and anair outlet opening, said openings being adjacent but separated from each other with the inlet opening forward of the outlet opening in the direction of drum rotation, said inlet opening being in the form of a narrow ax- 4 ially extending slot and said outlet opening having a cross-sectional area greater than that of said inlet opening.

2. A laundry drier as set forth in claim 1 comprising a nozzle-like air guide means contiguous with the edge of said housing surrounding said inlet opening, said nozzle-like guide means being inclined to the radius of said housing to direct the incoming air away from said outlet opening and generally tangentially of the drum in the direction of drum rotation.

3. A laundry drier as set forth in claim 2 wherein said openings are disposed in the lower part of said housin to supply dry air into and beneath laundry in the drum.

' HENRICUS C. A. ZWAARD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,385,223 Moore Sept. 18, 1945 2,477,820 Pokras Aug. 2, 1949 FOREIGN PATENTS Number Country Date 631,346 Great Britain Jan. 2, 1941 

